POLYMETHACRYLIMIDE

Polymethacrylimide (PMI) rigid foams as the core material for composites used in buses, aerospace launch vehicles, commercial and military aeroplanes, unmanned aerial vehicles, helicopters, ships, high-speed trains. Formula One racing cars, high-performance bicycles, cross-country skis. .. 

Polymethacrylimide (PMI) rigid foams as core material for composites used for X-ray tables... 

Table 6.20 shows some examples of the properties of polymethacrylimide foam. 

Sommer et al. [60] present a successful new application combining the GMT/ foaming processes (PP/PMI polymethacrylimide). 

Polymethacrylimides Polymethoenyllmide Controlled density Can be foamed in sitn Poor fire performance... 

Fourteen insulations were examined in this study. The insulations included three types of polyurethane, three varieties of polymethacrylimide, one polybenzimidazole, two polyisocyanurates, two polymetric isocyanate foams (one with chopped fiberglass reinforcement, one without), a modified isocyanate foam, and two insulation systems (one of polymeric isocyanate foam, one of toluenedi isocyanate foam, both with two vapor barriers and fiberglass reinforcement) ... 

Maximum in-plane tensile and compressive thermal stresses for square 15 cm thick polymethacrylimide foam bonded to an aluminum plate (foam surface temperature 317 K aluminum temperature 20 K). 

Polymethacrylimide. Based on previous experience with cryogenic foams for a hypersonic application and calculations that indicated the highest margin of any of the foams between the ultimate stress of the foam and the anticipated thermal stress, the pol3nnethacrylimide foam insulations (Rohacell 31, 51, and 41S) were leading candidates for the subsonic transport application at the onset of the test program. However, the thermal cycle performance, as shown in Fig. 13a, was poorer than that shown for the best polyurethane foams. 

Rohacell 31, a 30 kg/m (1.87 Ibm/ft ) density foam, displayed the best combined thermal and physical performances of polymethacrylimide materials. After the first few warm-up periods, short hairline surface cracks were observed. However, as of the writing of this paper, the Rohacell 31 specimen has sustained over 1600 thermal cycles with little degradation of the thermal performance. 

Each generic foam type had a characteristic failure mode. Polyurethane foams exhibited fine hairline through cracks that grew in length and width polymethacrylimide foams exhibited arc-shaped surface cracks that grew in depth and length the polyisocyanurate foams became soft and mushy on the side bonded to the tank. Insulations poured or sprayed in layers failed at the interlayer boundaries. 

A further reaction shown by poly(acrylic acid) and poly(methacrylic acid) is with ammonia to form cyclic imides. Polymethacrylimide is prepared commercially by heating a copolymer of methacrylic acid and methacrylonitrile with an ammonia-producing compound (e.g. urea or ammonium hydrogen carbonate) at about 200°C ... 

Both thermoplastic and thermosetting polymers are used as rigid foam materials these include (and are ranked from least to most expensive) polystyrene, phenol-formaldehyde (phenolic), polyurethane, poly(vinyl chloride), polypropylene, polyetherimide, and polymethacrylimide. 

Ammonium Benzoate Polyphenylene Ether, Modified 9 Polymethacrylimide (PMI) 1-8... 

Polyetherimide (PEI) Polymethacrylimide (PMI) 8 8 see d-Limonene Drain Cleaners (FEP) Fluoropolymer 9 9... 

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